1. Field of the Invention
This invention relates to the formation of a spark induced automotive engine gasoline fraction having a low Reid Vapor Pressure (RVP). More particularly, this invention relates to the processing of natural gasoline to form a low RVP gasoline fraction.
2. Description of the Prior Art
Natural gasoline is a hydrocarbonaceous liquid that spontaneously condenses from natural gas at ambient conditions of temperature and pressure naturally occurring at the earth's surface. It is predominantly composed of hydrocarbons having from 4 to 9, inclusive, carbon atoms per molecule (C4-C9, inclusive), and has a boiling range of from about 77 to about 430° F. (F).
Reid Vapor Pressure is determined by a well known analytical method for measuring the vapor pressure of petroleum products. Basically, a liquid sample is introduced into a chamber, and then immersed in a bath at 100 F until a constant pressure is observed. It is the difference, or partial pressure, produced by the sample at 100 F pursuant to ASTM test method D.
By today's standards in respect of reduced pollutant emissions from the operation of an automotive engine, natural gasoline is unacceptable in its original form because it has a very high RVP, e.g., often about 13 psi and higher. This high RVP characteristic makes natural gasoline unsuitable for addition, unaltered, to the automotive gasoline pool (gasoline pool) in large volumes.
It is, however, with current tight gasoline supplies, highly desirable to render natural gasoline suitable for addition to the overall gasoline pool in large volumes, and this invention provides just such a procedure.